Recently, as many bicycle paths have been opened, the people who ride a bicycle are increasing. However, a handle bar of a conventional bicycle provides merely a simple function to a rider with regard to adjusting a direction of the bicycle because a grip part is only simply installed at the handle bar.
Thus, the conventional bicycle has no means for signaling a rider's moving direction to another rider who comes on from the front or the back.
That is, in the case of a car, since a turn signal lamp is installed at the car, a rider can easily signal his or her driving direction to another rider who comes on from the back via a means for turning on and off the right or left turn signal lamp. However, it is problematic in that the bicycle has no means for signaling the rider's driving direction to another rider who comes on from the back.
Also, even though a turn signal lamp of the conventional bicycle is presented, it is for a user difficult to distinguish directions because such a turn signal lamp has a small width.
In particular, it is difficult for the existing turn signal lamp to substantially control or display a direction upon sudden stop or stop because there is no brake lamp, and thus there is the high risk of a rear collision.